diff --git a/docs/TESTING.md b/docs/TESTING.md
index 4f64345cf..b2e97601f 100644
--- a/docs/TESTING.md
+++ b/docs/TESTING.md
@@ -36,4 +36,11 @@ original request and the one for the destination. Check out the
 `wikipedia.response` and `wikipedia_redirected.response` files in 
 `spec/fixtures/oneboxer` for an example. You can also consider working directly 
 with the final URL for simplicity.
-   
\ No newline at end of file
+
+
+## MailCatcher
+
+Discourse depends heavily on (sending) email for notifications. We use [MailCatcher](http://mailcatcher.me/) 
+to test emails. It's super convenient!
+
+> MailCatcher runs a super simple SMTP server which catches any message sent to it to display in a web interface. Run mailcatcher, set your favourite app to deliver to smtp://127.0.0.1:1025 instead of your default SMTP server, then check out http://127.0.0.1:1080 to see the mail that's arrived so far.